A decentralized location service

Models, Methodologies and Applications, 2010

The idea of sharing resources across the network has become very popular during the last few years, leading to a diversified scenario in which shared resources include not only files and videos but also storage and CPU cycles. A new trend is to extend this paradigm toward a distributed architecture in which multiple network nodes cooperate to provide services in a distributed fashion, thus ensuring robustness and scalability. Peer-to-peer (P2P) overlays are the natural solution to achieve this goal as, thanks to their simplicity and flexibility, they can change their topology in order to fit the needs of the different kinds of services that can be provided on top of them. This chapter focuses on the indexing of nodes (i.e., the service providers) in these P2P systems, presenting the state-of-the-art solutions concerning the P2P-based indexing architectures and a taxonomy of possible services that can be built upon different overlay structures. Finally, emphasis is given to mechanisms implementing service selection based on some cost parameters (e.g., topological proximity) in order to introduce some mechanism based on optimality in case multiple service providers exist. on the different machines, but also application services (i.e. application software providing some sort of service to other users over the network).

2001

Peer-to-peer computing is a term used to describe the current trend toward utilizing the full resources available within a widely distributed network of nodes with increasing computational power. These resources include the exchange of information, processing cycles, cache storage, and disk storage for files. Routing, locating and transmitting of resources, becomes an extremely important issue then. First steps toward robust peer-to-peer systems include extensions of centralized models of resource sharing (e.g. Napster), but more recent attempts acknowledge the limitations of such systems and also address issues of performance, reliability, scalability, maintenance, and usability. We focus on the problem of sharing data and in the context of these issues offer a survey of the following systems: Napster, Gnutella, TRIAD, Pastry, Plaxton, Tapestry, Chord, and CAN. The upshot is that we isolate what we see as both the crucial issues and solutions to the challenge of routing in the peer-to-peer environment, give a comparative summary for all systems. Finally based on framework and analysis, we propose some further questions and potential approaches for future investigation.

IEEE/ACM Transactions on Networking, 2003

A fundamental problem that confronts peer-to-peer applications is the efficient location of the node that stores a desired data item. This paper presents Chord, a distributed lookup protocol that addresses this problem. Chord provides support for just one operation: given a key, it maps the key onto a node. Data location can be easily implemented on top of Chord by associating a key with each data item, and storing the key/data pair at the node to which the key maps. Chord adapts efficiently as nodes join and leave the system, and can answer queries even if the system is continuously changing. Results from theoretical analysis and simulations show that Chord is scalable: Communication cost and the state maintained by each node scale logarithmically with the number of Chord nodes.

INTERNATIONAL SERIES IN …, 2003

2001

2018

The major aim of Location Based Services (LSB) is based on the location, it is used to provide services like food ordering system, Google map and some kind of e-shopping websites are completely based on locations. Based on the user location LSB provide continuous report to the un trusted server to obtain the services which can avoid privacy risks.LBS have existing privacy-preserving techniques as requiring a fully-trusted third party, it offers limited privacy guarantees and incurring high communication overhead. In this paper, we propose a userdefined privacy grid system which is called as dynamic grid system (DGS). Privacy-preserving snapshot and continuous LBS have four effective requirements. . (1) A semi-trusted third party is responsible for matching operations correctly and it does not have any information about a user's location. (2) Secure snapshot and continuous location privacy is guaranteed to defined adversary models. (3) The communication cost for the user does not...

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 2012

Peer-to-peer service overlay networks (P2P SON) are increasingly being infrastructure providers for networking services, allowing service providers to cooperatively offer and run a flexible set of services. Regarding this condition, the selection of peers is a key issue for improving resource usage; service performance, and ultimately end users Quality of Experience (QoE). This paper presents an approach to best peer selection in a three-tier P2P SON architecture, allowing the splitting of service business functions and peer selection functions. The proposed best peer selection approach is evaluated by simulation, using a literature available geographic positioning metrich that takes into account real delay and jitter made available by the CAIDA project and Max-Mind's free database. The simulation results show the consistency and good performance of the proposed peer selection approach. ⋆ This work was partially funded by Portuguese Foundation for Science and Technology (grant SFRH/BD/45683/2008).

IEEE Communications Surveys and Tutorials, 2008

Efficient Resource discovery mechanism is one of the fundamental requirement for Grid computing systems, as it aids in resource management and scheduling of applications. Resource discovery activity involve searching for the appropriate resource types that match the user's application requirements. Various kinds of solutions to grid resource discovery have been suggested, including the centralised and hierarchical information server approach. However, both of these approaches have serious limitations in regards to scalability, fault-tolerance and network congestion. To overcome these limitations, indexing resource information using a decentralised (such as Peer-to-Peer (P2P)) network model has been actively proposed in the past few years.

IEEE/ACM Transactions on Networking, 1995

A fundamental problem that confronts peer-to-peer applications is to efficiently locate the node that stores a particular data item. This paper presents Chord, a distributed lookup protocol that addresses this problem. Chord provides support for just one operation: given a key, it maps the key onto a node. Data location can be easily implemented on top of Chord by associating a key with each data item, and storing the key/data item pair at the node to which the key maps. Chord adapts efficiently as nodes join and leave the system, and can answer queries even if the system is continuously changing. Results from theoretical analysis and simulations show that Chord is scalable, with communication cost and the state maintained by each node scaling logarithmically with the number of Chord nodes. of nearby servers, anonymity, search, authentication, and hierarchical naming. Despite this rich set of features, the core operation in most peer-to-peer systems is efficient location of data items. The contribution of this paper is a scalable protocol for lookup in a dynamic peer-to-peer system with frequent node arrivals and departures.

This paper presents the design and evaluation of Pastry, a scalable, distributed object location and routing substrate for wide-area peer-to-peer applications. Pastry performs application-level routing and object location in a potentially very large overlay network of nodes connected via the Internet. It can be used to support a variety of peer-to-peer applications, including global data storage, data sharing, group communication and naming. Each node in the Pastry network has a unique identifier (nodeId). When presented with a message and a key, a Pastry node efficiently routes the message to the node with a nodeId that is numerically closest to the key, among all currently live Pastry nodes. Each Pastry node keeps track of its immediate neighbors in the nodeId space, and notifies applications of new node arrivals, node failures and recoveries. Pastry takes into account network locality; it seeks to minimize the distance messages travel, according to a to scalar proximity metric like the number of IP routing hops. Pastry is completely decentralized, scalable, and self-organizing; it automatically adapts to the arrival, departure and failure of nodes. Experimental results obtained with a prototype implementation on an emulated network of up to 100,000 nodes confirm Pastry's scalability and efficiency, its ability to self-organize and adapt to node failures, and its good network locality properties.